package com.example.rpc.common.util;

import com.dyuproject.protostuff.LinkedBuffer;
import com.dyuproject.protostuff.ProtostuffIOUtil;
import com.dyuproject.protostuff.Schema;
import com.dyuproject.protostuff.runtime.RuntimeSchema;

import org.objenesis.Objenesis;
import org.objenesis.ObjenesisStd;

import java.util.Map;
import java.util.concurrent.ConcurrentHashMap;

/**
 * 序列化工具(基于Protostruff实现)
 * @Author Anita
 * @Date 2017/12/25 15:16
 */
public class SerializationUtil {
    private static Map<Class<?>,Schema<?>> cachedSchema = new ConcurrentHashMap<>();
    private static Objenesis objenesis = new ObjenesisStd(true);
    private SerializationUtil(){}

    /**
     * 序列化（对象->字节数组）
     * @param obj
     * @param <T>
     * @return
     */
    public static <T> byte[] serialize(T obj){
        Class<T> cls = (Class<T>) obj.getClass();
        LinkedBuffer buffer = LinkedBuffer.allocate(LinkedBuffer.DEFAULT_BUFFER_SIZE);
        try{
            Schema<T> schema = getSchema(cls);
            return ProtostuffIOUtil.toByteArray(obj,schema,buffer);
        }catch(Exception e){
            throw new IllegalStateException(e.getMessage(),e);
        } finally {
            buffer.clear();
        }
    }

    /**
     * 反序列化（字节数组->对象）
     * @param data
     * @param cls
     * @param <T>
     * @return
     */
    public static <T> T deserialize(byte[] data,Class<T> cls){
        try{
            T message = objenesis.newInstance(cls);
            Schema<T> schema = getSchema(cls);
            ProtostuffIOUtil.mergeFrom(data,message,schema);
            return message;
        }catch(Exception e){
            throw new IllegalStateException(e.getMessage(),e);
        }
    }

    private static <T> Schema<T> getSchema(Class<T> cls){
        Schema<T> schema = (Schema<T>) cachedSchema.get(cls);
        if(schema == null){
            schema = RuntimeSchema.createFrom(cls);
            cachedSchema.put(cls,schema);
        }
        return schema;
    }

}
